It is desired that feeds used for livestock raising, particularly feeds for raising chickens and pigs satisfy high-level conditions such as high nutrition value and long storage life. As a feed satisfying such conditions, feeds obtained by fermenting raw materials by bacteria such as koji fungus (Aspergillus) have attracted attention and development of these feeds have been made.
For example, Patent Literature 1 by the present inventors discloses a method for producing a malt (koji)-blended feed, characterized by including blending Aspergillus with at least two types of raw materials selected from fiber feeds, grains and organic waste and growing Aspergillus therein. The malt-blended feed, which is provided by fermenting fiber feeds, grains and organic waste by Aspergillus, can facilitate fattening of farm animals without harmful effects such as ureteral stone and diarrhea, and improve quality of meat.
Patent Literature 2 by the present inventors discloses a method for treating food waste, which includes fermenting a raw material containing food waste by koji fungus to obtain a liquid material. The literature discloses that the koji fungus is a bacterium belonging to the genus Aspergillus and having an ability to produce citric acid; the liquid material contains citric acid produced by the Aspergillus; and the pH is 5.5 or less. The method for treating food waste is developed for using food waste as a feed, storing the feed without decay, and preventing reduction in quality of meat caused by oily components and reduction in growth caused by unstable components.